Japan's atomic regulator is “very close” to finishing its review of two reactors in southern Japan that are slated to be the first to restart under new rules introduced since the Fukushima nuclear disaster, one of its commissioners told Reuters.

Restarting the first reactors will end the country's longest period without nuclear power. Prior to the meltdowns at the Fukushima Daiichi plant in 2011, Japan was the third biggest user of the resource.

The disaster led to the eventual shut down of all reactors and operators were required to relicense their reactors after the disaster highlighted regulatory failings and led to the creation of a new, more independent, oversight body.

“As for the licensing procedure, it is very close to the end,” Toyoshi Fuketa, a commissioner at the Nuclear Regulatory Authority, told Reuters at the close of a seminar on decommissioning on Wednesday.

Fuketa said he could not give a firm timeframe.

Kyushu Electric Power Co. received the first approval of a three-step process in September for its Sendai Nos. 1 and 2 reactors, which were commissioned about 30 years ago.

Pre-inspection needed

Once the licensing procedure is passed, the reactors need to go through a pre-service inspection before they can be restarted.

“We need to have a period for inspection and this is the first experience for Kyushu and for us,” Fuketa said. “It will take a certain time, quite difficult to say" how long the process will take.

Fuketa anticipated hitches in the start-up because both reactors have been shut down for an extended period. Sendai No. 1 has been idle since May 2011, while the No. 2 reactor has been shut since September 2011.

“I also personally expect we will face minor troubles - not an accident - as they have been down for a certain period of time,” Fuketa said, referring to possible equipment failures.

Japan's government is aiming to restart the first nuclear reactor sometime around June, sources told Reuters earlier this year. Kyushu Electric said last month it is aiming to get ready to reboot the No. 1 reactor at the end of June.

Prime Minister Shinzo Abe's government has been pushing to bring some of the country's reactors back online, arguing they are key to economic growth.

But the move would be controversial in a nation where most oppose nuclear power.

Memories are still fresh of the worst atomic crisis since Chernobyl in 1986. Opinion polls show a consistent majority oppose restarts, even though power bills have risen.